Independent auditor’s report and assurance report

Independent auditor’s report

To: the shareholders and the supervisory board of Alliander N.V.

Report on the audit of the financial statements 2023 included in the annual report

Our opinion

We have audited the financial statements 2023 of Alliander N.V., based in Arnhem. The financial statements comprise the consolidated financial statements and the company financial statements.

In our opinion:

• The accompanying consolidated financial statements give a true and fair view of the financial position of Alliander N.V. as at 31 December 2023, and of its result and its cash flows for 2023 in accordance with International Financial Reporting Standards as adopted by the European Union (EU-IFRS) and with Part 9 of Book 2 of the Dutch Civil Code.

• The accompanying company financial statements give a true and fair view of the financial position of Alliander N.V. as at 31 December 2023, and of its result for 2023 in accordance with Part 9 of Book 2 of the Dutch Civil Code.

The consolidated financial statements comprise:

1. The consolidated statement of financial position as at 31 December 2023.

2. The following statements for 2023: the consolidated income statement, the consolidated statements of comprehensive income, changes in equity and cash flows.

3. The notes comprising material accounting policy information and other explanatory information.

The company financial statements comprise:

1. The company balance sheet as at 31 December 2023.

2.  The company profit and loss account for 2023.

3. The notes comprising a summary of the accounting policies and other explanatory information.

Basis for our opinion

We conducted our audit in accordance with Dutch law, including the Dutch Standards on Auditing. Our responsibilities under those standards are further described in the 'Our responsibilities for the audit of the financial statements' section of our report.

We are independent of Alliander N.V. in accordance with the EU Regulation on specific requirements regarding statutory audit of public-interest entities, the Wet toezicht accountantsorganisaties (Wta, Audit firms supervision act), the Verordening inzake de onafhankelijkheid van accountants bij assurance-opdrachten (ViO, Code of Ethics for Professional Accountants, a regulation with respect to independence) and other relevant independence regulations in the Netherlands. Furthermore, we have complied with the Verordening gedrags- en beroepsregels accountants (VGBA, Dutch Code of Ethics).

We believe the audit evidence we have obtained is sufficient and appropriate to provide a basis for our opinion.

Information in support of our opinion

We designed our audit procedures in the context of our audit of the financial statements as a whole and in forming our opinion thereon. The following information in support of our opinion was addressed in this context, and we do not provide a separate opinion or conclusion on these matters.

Materiality

Based on our professional judgement we determined the materiality for the financial statements as a whole at € 28,000,000. The materiality is based on 4% of cash flow from operating activities. We have also taken into account misstatements and/or possible misstatements that in our opinion are material for the users of the financial statements for qualitative reasons.

We agreed with the supervisory board that misstatements in excess of € 1,400,000, which are identified during the audit, would be reported to them, as well as smaller misstatements that in our view must be reported on qualitative grounds.

Scope of the group audit

Alliander N.V. is at the head of a group of entities. The financial information of this group is included in the consolidated financial statements of Alliander N.V.

Our group audit mainly focused on significant group entities Alliander N.V. and Liander N.V.

We haveperformed audit procedures ourselves at group entities Alliander N.V. and Liander N.V. For other group entities we performed review procedures or specific audit procedures.

By performing the procedures mentioned above at group entities, together with additional procedures at group level, we have been able to obtain sufficient and appropriate audit evidence about the group's financial information to provide an opinion on the consolidated financial statements.

Audit approach fraud risks

We identified and assessed the risks of material misstatements of the financial statements due to fraud. During our audit we obtained an understanding of the entity and its environment and the components of the system of internal control, including the risk assessment process and management's process for responding to the risks of fraud and monitoring the system of internal control and how the supervisory board exercises oversight, as well as the outcomes.

We evaluated the design and relevant aspects of the system of internal control and in particular the fraud risk assessment, as well as among others the code of conduct, whistle blower procedures and incident registration. We evaluated the design and the implementation and, where considered appropriate, tested the operating effectiveness, of internal controls designed to mitigate fraud risks.

As part of our process of identifying fraud risks, we evaluated fraud risk factors with respect to financial reporting fraud, misappropriation of assets and bribery and corruption in close co-operation with our forensic specialists. We evaluated whether these factors indicate that a risk of material misstatement due fraud is present.

We identified the following fraud risks and performed the following specific procedures:

Based on the auditing standards, we considered the assumed fraud risk related to management's breach of internal controls, including whether there are indications of tendency in the group's management that may pose a risk of a material misstatement resulting from fraud.

We have performed substantive procedures, including testing journal entries, assessing estimates for bias (including retrospective assessment of significant estimates from the previous financial year), and testing the substantiation of the adjustments made during the preparation of the annual accounts.

We incorporated elements of unpredictability in our audit. We also considered the outcome of our other audit procedures and evaluated whether any findings were indicative of fraud or non-compliance.

We considered available information and made enquiries of members of the Management Board , management (including legal department and Internal Audit) and the supervisory board.

We tested the appropriateness of journal entries recorded in the general ledger and other adjustments made in the preparation of the financial statements.

We evaluated whether the selection and application of accounting policies by the entity, particularly those related to subjective measurements and complex transactions, may be indicative of fraudulent financial reporting.

This did not reveal any indications of fraud that could lead to a material misstatement due to fraud.

Audit approach compliance with laws and regulations

We assessed the laws and regulations relevant to the entity through discussion with legal department, reading minutes and reports of internal audit.

Where material to the related financial statements, based on our risk assessment procedures and while realizing that the effects from non-compliance could considerably vary, we considered the following laws and regulations: (corporate) tax law, the requirements under the International Financial Reporting Standards as adopted by the European Union (EU-IFRS) and Part 9 of Book 2 of the Dutch Civil Code as being laws and regulations with a direct effect on the financial statements.

We obtained sufficient appropriate audit evidence regarding provisions of those laws and regulations generally recognized to have a direct effect on the financial statements.

Apart from these, the entity is subject to other laws and regulations where the consequences of non-compliance could have a material effect on amounts and/or disclosures in the financial statements, for instance, through imposing fines or litigation.

Given the nature of the entity's business and the complexity of European public procurement regulations, the Act on Independent Network Management, the Electricity Act 1998 and the Gas Act and other laws and regulations, there is a risk of non-compliance with the requirements of such laws and regulations.

Our procedures are more limited with respect to these laws and regulations that do not have a direct effect on the determination of the amounts and disclosures in the financial statements. Compliance with these laws and regulations may be fundamental to the operating aspects of the business, to the entity's ability to continue its business, or to avoid material penalties (e.g., compliance with the terms of operating licenses and permits or compliance with environmental regulations) and therefore non-compliance with such laws and regulations may have a material effect on the financial statements. Our responsibility is limited to undertaking specified audit procedures to help identify non-compliance with those laws and regulations that may have a material effect on the financial statements. Our procedures are limited to (i) inquiry of management, the Supervisory Board, the Executive Board and others within the entity as to whether the entity is in compliance with such laws and regulations and (ii) inspecting correspondence, if any, with the relevant licensing or regulatory authorities to help identify non-compliance with those laws and regulations that may have a material effect on the financial statements.

Naturally, we remained alert to indications of (suspected) non-compliance throughout the audit.

Finally, we obtained written representations that all known instances of (suspected) fraud or non-compliance with laws and regulations have been disclosed to us.

Audit approach going concern

We are responsible for obtaining a reasonable level of assurance that the group is capable of maintaining its continuity. It is the responsibility of the management to assess whether the group is capable of maintaining its continuity and to disclose in the annual accounts any events or circumstances that might give rise to significant doubt about the group's ability to maintain its continuity.

As disclosed on page 138, the accounting policies used in the financial statements are based on the assumption of the company's continuity.

We reviewed management's assessment of the assumption of continuity of Alliander N.V., including the relevant disclosures in the financial statements of Alliander N.V. 2023.

This includes evaluating:

• The liquidity and financing elements in Alliander's business plan for 2024-2028 and the underlying developments and assumptions for both short and long term.

• Treasury reports 2023.

• The most recent credit ratings from Moody's and S&P.

Based on our work, we have no findings to report.

Our key audit matters

Key audit matters are those matters that, in our professional judgement, were of most significance in our audit of the financial statements. We have communicated the key audit matters to the supervisory board. The key audit matters are not a comprehensive reflection of all matters discussed.

These matters were addressed in the context of our audit of the financial statements as a whole and in forming our opinion thereon, and we do not provide a separate opinion on these matters.

Report on the other information included in the annual report

The annual report contains other information, in addition to the financial statements and our auditor's report thereon.

The other information consists of:

•  Management Board's Report (page 3-130).

• Other information.

Based on the following procedures performed, we conclude that the other information:

• Is consistent with the financial statements and does not contain material misstatements.

• Contains the information regarding the management report and the other information as required by Part 9 of Book 2 of the Dutch Civil Code.

We have read the other information. Based on our knowledge and understanding obtained through our audit of the financial statements or otherwise, we have considered whether the other information contains material misstatements.

By performing these procedures, we comply with the requirements of Part 9 of Book 2 of the Dutch Civil Code and the Dutch Standard 720. The scope of the procedures performed is substantially less than the scope of those performed in our audit of the financial statements.

Management is responsible for the preparation of the other information, including the Management Board's Report in accordance with Part 9 of Book 2 of the Dutch Civil Code, and the other information as required by Part 9 of Book 2 of the Dutch Civil Code.

Report on other legal and regulatory requirements

Engagement

We were engaged by the supervisory board as auditor of Alliander N.V. on July 29, 2015, as of the audit for the year 2016 and have operated as statutory auditor ever since that financial year. In December 2019 we were reappointed for the audit of the financial years 2020 and 2021 and in December 2021 we were reappointed for the audit of the financial years 2022 and 2023. The Supervisory Board is mandated to this end by the shareholders.

No prohibited non-audit services

We have not provided prohibited non-audit services as referred to in Article 5(1) of the EU Regulation on specific requirements regarding statutory audit of public-interest entities.

Description of responsibilities regarding the financial statements

Responsibilities of management and the supervisory board for the financial statements

Management is responsible for the preparation and fair presentation of the financial statements in accordance with EU-IFRS and Part 9 of Book 2 of the Dutch Civil Code. Furthermore, management is responsible for such internal control as management determines is necessary to enable the preparation of the financial statements that are free from material misstatement, whether due to fraud or error.

As part of the preparation of the financial statements, management is responsible for assessing the company's ability to continue as a going concern. Based on the financial reporting frameworks mentioned, management should prepare the financial statements using the going concern basis of accounting unless management either intends to liquidate the company or to cease operations, or has no realistic alternative but to do so.

Management should disclose events and circumstances that may cast significant doubt on the company's ability to continue as a going concern in the financial statements.

The supervisory board is responsible for overseeing the company's financial reporting process.

Our responsibilities for the audit of the financial statements

Our objective is to plan and perform the audit assignment in a manner that allows us to obtain sufficient and appropriate audit evidence for our opinion.

Our audit has been performed with a high, but not absolute, level of assurance, which means we may not detect all material errors and fraud during our audit.

Misstatements can arise from fraud or error and are considered material if, individually or in the aggregate, they could reasonably be expected to influence the economic decisions of users taken on the basis of these financial statements. The materiality affects the nature, timing and extent of our audit procedures and the evaluation of the effect of identified misstatements on our opinion.

We have exercised professional judgement and have maintained professional scepticism throughout the audit, in accordance with Dutch Standards on Auditing, ethical requirements and independence requirements. Our audit included among others:

• Identifying and assessing the risks of material misstatement of the financial statements, whether due to fraud or error, designing and performing audit procedures responsive to those risks, and obtaining audit evidence that is sufficient and appropriate to provide a basis for our opinion. The risk of not detecting a material misstatement resulting from fraud is higher than for one resulting from error, as fraud may involve collusion, forgery, intentional omissions, misrepresentations, or the override of internal control.

• Obtaining an understanding of internal control relevant to the audit in order to design audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the company's internal control.

• Evaluating the appropriateness of accounting policies used and the reasonableness of accounting estimates and related disclosures made by management.

• Concluding on the appropriateness of management's use of the going concern basis of accounting, and based on the audit evidence obtained, whether a material uncertainty exists related to events or conditions that may cast significant doubt on the company's ability to continue as a going concern. If we conclude that a material uncertainty exists, we are required to draw attention in our auditor's report to the related disclosures in the financial statements or, if such disclosures are inadequate, to modify our opinion. Our conclusions are based on the audit evidence obtained up to the date of our auditor's report. However, future events or conditions may cause the company to cease to continue as a going concern.

• Evaluating the overall presentation, structure and content of the financial statements, including the disclosures.

• Evaluating whether the financial statements represent the underlying transactions and events in a manner that achieves fair presentation.

Because we are ultimately responsible for the opinion, we are also responsible for directing, supervising and performing the group audit. In this respect we have determined the nature and extent of the audit procedures to be carried out for group entities. Decisive were the size and/or the risk profile of the group entities or operations. On this basis, we selected group entities for which an audit or review had to be carried out on the complete set of financial information or specific items.

We communicate with the supervisory board regarding, among other matters, the planned scope and timing of the audit and significant audit findings, including any significant findings in internal control that we identified during our audit. In this respect we also submit an additional report to the audit committee in accordance with Article 11 of the EU Regulation on specific requirements regarding statutory audit of public-interest entities. The information included in this additional report is consistent with our audit opinion in this auditor's report.

We provide the supervisory board with a statement that we have complied with relevant ethical requirements regarding independence, and to communicate with them all relationships and other matters that may reasonably be thought to bear on our independence, and where applicable, related safeguards.

From the matters communicated with the supervisory board, we determine the key audit matters: those matters that were of most significance in the audit of the financial statements. We describe these matters in our auditor's report unless law or regulation precludes public disclosure about the matter or when, in extremely rare circumstances, not communicating the matter is in the public interest.

Amsterdam, February 28, 2024

Assurance report with partially reasonable and partially limited assurance of the independent auditor on the non-financial information in the annual report of Alliander N.V.

To the shareholders and the supervisory board of Alliander N.V.

The management board of Alliander N.V. (‘the Company’) engaged us to provide assurance on a selection of non-financial information in the Annual Report 2023 (‘the Report’). Our engagement consisted of a combination of limited assurance (leading to a ‘conclusion’) and reasonable assurance (leading to an ‘opinion’).

Our conclusion

Based on our procedures performed and the assurance information obtained, nothing has come to our attention that causes us to believe that the non-financial information in the accompanying annual report does not present fairly, in all material respects:

• The policy and business operations with regard to non-financial information.

• Business operations, the applicable related events and achievements for the year 2023 in accordance with the applicable criteria as included in the ‘Criteria’ section of our report.

We were engaged to provide limited assurance on the following chapters (‘the reviewed information’):

• Our story in 2023 (pages 3-6)

• About this report (pages 7-9)

• Profile of Alliander (pages 10-23)

• The value we create, presented in the chapters:

• • Our network: high supply reliability at a low cost (pages 25-36)

  •  Making the energy supply and our organisation sustainable (pages 37-50)

  • Ensuring a safe energy network, a safe working environment and a safe data environment (pages 51-55)

  • Being an attractive, inclusive employer with equal opportunities for all (pages 56-65)

  •  A creditworthy company with solid returns (pages 66-88)

  • Our impact on society (pages 89-100), including impact cases

  •  Dilemmas and lessons learned (pages 101-102)

We did not perform review procedures on the information about the EU Taxonomy as disclosed in the chapter ‘EU Taxonomy’ on page 82-87.

Our opinion

In our opinion, the non-financial information in the accompanying annual report presents fairly, in all material respects:

• The policy with regard to non-financial information.

• Business operations, the applicable related events and achievements for the year 2023 in accordance with the applicable criteria as included in the ‘Criteria’ section of our report.

We were engaged to provide reasonable assurance on the following information (‘the audited information’):

• The summarized materiality assessment presented in the chapter ‘About this report’ (page 7-9) and the extensive materiality assessment presented in the chapter ‘Other Information, Materiality test’ (page 209-212).

• The table "Objectives and results" in the chapter "Profile of Alliander" (page 22-23).

Basis for our conclusion and our opinion

We have performed our assurance engagement on the non-financial information in accordance with Dutch law, including Dutch Standard 3810N ‘Assurance-opdrachten inzake duurzaamheidsverslaggeving’ (Assurance engagements relating to sustainability reports). This engagement is focused on obtaining partially reasonable assurance and partially limited assuranceOur responsibilities under this standard are further described in the section ‘Our responsibilities for the assurance engagement on the non-financial information’.

We are independent of Alliander in accordance with the ‘Verordening inzake de onafhankelijkheid van accountants bij assurance-opdrachten’ (ViO, Code of Ethics for Professional Accountants, a regulation with respect to independence) and other relevant independence requirements in the Netherlands. This includes that we do not perform any activities that could result in a conflict of interest with our independent assurance engagement. Furthermore, we have complied with the ‘Verordening gedrags- en beroepsregels accountants’ (VGBA, Dutch Code of Ethics for Professional Accountants).

We believe that the assurance evidence we have obtained is sufficient and appropriate to provide a basis for our opinion.

Criteria

The criteria applied for the preparation of the non-financial information are the GRI Sustainability Reporting Standards (GRI Standards) and the criteria supplementally applied as disclosed in the chapter ‘Other information’ of the annual report.

The non-financial information is prepared in accordance with the GRI Standards. The GRI Standards used are listed in the GRI Content Index as published on the company’s website.

The comparability of non-financial information between entities and over time may be affected by the absence of a uniform practice on which to draw, to evaluate and measure this information. This allows for the application of different, but acceptable, measurement techniques.

Consequently, the non-financial information needs to be read and understood together with the criteria applied.

Materiality

Based on our professional judgement we determined materiality levels for each relevant matter in the non-financial information. When evaluating our materiality levels, we considered quantitative and qualitative aspects as well as the relevance of information for both stakeholders and the company.

We agreed with the supervisory board that misstatements which are identified during the assurance engagement and which in our view must be reported on quantitative or qualitative grounds, would be reported to them.

Limitations to the scope of our assurance engagement

The non-financial information includes prospective information such as ambitions, strategy, plans, expectations, and estimates and risk assessments. Prospective information relates to events and actions that have not yet occurred and may never occur. We do not provide any assurance on the assumptions and achievability of this prospective information.

The references to external sources or websites in the non-financial information are not part of the non-financial information as included in the scope of our assurance engagement. We therefore do not provide assurance on this information.

Our opinion is not modified in respect to these matters.

Responsibilities of the management board and the supervisory board for the non-financial information

The management board is responsible for the preparation and fair presentation of the non-financial information in accordance with the criteria as included in the ‘Criteria’ section, including the identification of stakeholders and the definition of material matters. The management board is also responsible for selecting and applying the criteria and for determining that these criteria are suitable for the legitimate information needs of stakeholders, considering applicable law and regulations related to reporting. The choices made by the management board regarding the scope of the non-financial information and the reporting policy are summarised in the chapter ‘Other non-financial information’ of the annual report.

Furthermore, the management board is responsible for such internal control as it determines is necessary to enable the preparation of the non-financial information that is free from material misstatement, whether due to fraud or error.

The supervisory board is responsible for overseeing the reporting process for the non-financial information of Alliander.

Our responsibilities for the assurance engagement on the non-financial information

Our responsibility is to plan and perform the assurance engagement in a manner that allows us to obtain sufficient and appropriate assurance evidence for our conclusion and our opinion.

The procedures performed to obtain limited assurance are aimed at determining the plausibility of the non-financial information. The procedures vary in nature and timing from, and are less in extent, than for a reasonable assurance engagement. The level of assurance obtained in a limited assurance engagement is therefore substantially less than the assurance that is obtained when a reasonable assurance engagement is performed.

Our assurance engagement has been performed with a high, but not absolute, level of assurance, which means we may not have detected all material errors and fraud during our assurance engagement.

We apply the ‘Nadere voorschriften kwaliteitssystemen)’ (NVKS, regulations for quality management systems) and accordingly maintain a comprehensive system of quality management including documented policies and procedures regarding compliance with ethical requirements, professional standards and other relevant legal and regulatory requirements.

Limited assurance procedures

Our review included among others:

• Performing an analysis of the external environment and obtaining an understanding of relevant social themes and issues, and the characteristics of the company.

• Evaluating the appropriateness of the criteria applied, their consistent application and related disclosures in the non-financial information. This includes the evaluation of the company’s materiality assessment and the reasonableness of estimates made by the management board.

• Obtaining an understanding of the systems and processes for collecting, reporting, and consolidating the non-financial information, including obtaining an understanding of internal control environment relevant to our assurance engagement, but not for the purpose of expressing an opinion on the effectiveness of the company’s internal control.

• Evaluating the procedures performed by the internal audit department of Alliander.

• Identifying and assessing the risks whether the non-financial information is misleading or unbalanced, or contains material misstatements, whether due to fraud or errors. Designing and performing further assurance procedures responsive to those risks, and obtaining assurance evidence that is sufficient and appropriate to provide a basis for our opinion. These procedures consisted among others of:

• • obtaining inquiries from management and relevant staff responsible for the sustainability strategy, policy and results;

  • obtaining inquiries from relevant staff responsible for providing the information for, carrying out internal procedures on, and consolidating the data in the non-financial information;

  • obtaining assurance evidence that the non-financial information reconciles with underlying records of the company;

  • reviewing, on a limited test basis, relevant internal and external documentation;

  • evaluating the data and trends and perform variance analysis to compare with prior year.

• Reconciling the relevant financial information with the financial statements.

• Evaluating the overall presentation and balanced content of the non-financial information.

• Considering whether the non-financial information as a whole, including the matters covered and disclosures, is clearly and adequately disclosed in accordance with the applicable criteria.

Reasonable assurance procedures

Complementary to the aforementioned procedures, our audit included the following:

• Obtaining an understanding of the systems and processes for collecting, reporting, and consolidating the non-financial information, including obtaining an understanding of internal control environment relevant to our assurance engagement, but not for the purpose of expressing an opinion on the effectiveness of the company’s internal control.

• Identifying and assessing the risks whether the non-financial information is misleading or unbalanced, or contains material misstatements, whether due to fraud or errors. Designing and performing further assurance procedures responsive to those risks, and obtaining assurance evidence that is sufficient and appropriate to provide a basis for our opinion. These procedures consisted among others of:

• • Evaluating the design and implementation and testing the operating effectiveness of the reporting systems and processes related to the information in the report.

  • Evaluating the data and trends.

• Evaluating internal and external documentation, on a test basis, to determine the reliability of the information in the report.

We communicate with the supervisory board regarding, among other matters, the planned scope and timing of the assurance engagement and significant findings, including any significant findings in internal control that we identify during our assurance engagement.

Amsterdam, February 28, 2024

Deloitte Accountants B.V.

Ben Dielissen